Re: LED Diffusion Lighthead for Omega D5
Great post! I've been pondering how to switch my D2 to a diffusion enlarger and this seems like a good way to go! To jp's point, the lag is probably the power inrush from the AC to DC power supply for the LEDs. I think you could fix that by using a relay controlled from the timer. So the timer is turning the relay off/on which would open/close the DC side of the circuit where the LEDs connect to. That keeps the LED power supply itself ready to go.
I haven't found a relay that is for switching a lower voltage using a high voltage for the switching though I'd imagine they exist (that or perhaps a transistor).
My concern here is those Ilford MG filters. I've gotten quite used to those so matching the wavelength there would be ideal. I wonder if warm-white LEDs might be closer in spectrum? I think the multicolored LED solution might be the best option. I think that's what the Intrepid 4x5 enlarger uses (actually wondering if I can augment their head on my D2...). And/or I wonder if RGB LEDs would work (you can find pretty dense RGB LED strips if space is tight, though not sure about light output). I'd still prefer filters over fiddling with colors. I think I would need/want a much more intelligent timer where I could easily dial in the desired filters for me to be happy with not using the gel filters.
In the interim, I read up a bit on making a diffusion panel for the Omega D2. I'm guessing something as simple as rice paper would either not provide even lighting or would transmit too much texture? If not, placing that on top of the negative carrier would work in a pinch?
I love the condenser look when it works but man can it be contrasty. Spotting hasn't been a huge issue (so far) but I definitely get more dust than I did on my Beseler 67. My tiny darkroom doesn't have room for two enlargers (and I prefer to print 4x5 most of the time anyway).
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Re: LED Diffusion Lighthead for Omega D5
Quote:
I read up a bit on making a diffusion panel for the Omega D2.
I'd consider a Chromega D head to convert an Omega enlarger into diffusion. There are still bargains to be had on ebay, seeing as the filters don't fade. I have a 'spare' D size head for my Omega enlarger already, but if I didn't I'd pick up another Chromega D while they are still available.
The longer lift rods you need to mount the Chromega head are at any USA hardware store.
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Re: LED Diffusion Lighthead for Omega D5
I was looking at those, but they require a special control box as well correct? I was having trouble finding both for a reasonable price.
Re: LED Diffusion Lighthead for Omega D5
Quote:
Originally Posted by
m00dawg
I was looking at those, but they require a special control box as well correct? I was having trouble finding both for a reasonable price.
The most economical power supply 412-021 is basically just a transformer in a box. Although the ELC lamp is a 24 volt lamp, it is my understanding that the transformer actually supplies 22.5 Volts to give a longer lamp life.
The fan and panel lamp operate on 120V, so the 120V is just passed through.
There are no other electrical or electronic components in the box with transformer.
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Re: LED Diffusion Lighthead for Omega D5
Quote:
Originally Posted by
m00dawg
I was looking at those, but they require a special control box as well correct? I was having trouble finding both for a reasonable price.
The 412-021 is the Standard Power Supply and is the most economical solution. It is basically just a transformer in a box. Although the ELC lamp is a 24 volt lamp, it is my understanding that the transformer actually supplies 22.5 Volts to give a longer lamp life.
The fan and panel lamp operate on 120V, so the 120V is just passed through.
There are no other electrical or electronic components in the box with transformer.
Attachment 185257
Re: LED Diffusion Lighthead for Omega D5
Quote:
Originally Posted by
ic-racer
I'd consider a Chromega D head to convert an Omega enlarger into diffusion. There are still bargains to be had on ebay, seeing as the filters don't fade. I have a 'spare' D size head for my Omega enlarger already, but if I didn't I'd pick up another Chromega D while they are still available.
The longer lift rods you need to mount the Chromega head are at any USA hardware store.
Attachment 185255
I had used the Chromega D diffusion head before I went to the Modern Enlarger Lamps (MEL) condenser LED head. It did the job and infinitely adjustable, dial-a-contrast was very nice.
However, the main things for me were that the constant fan noise was driving me to distraction and the heat from the lamp would quickly warp the negative as it heated up (I did not want to use a glass negative carrier due to the 4 additional surfaces that would need to be cleaned). If you can deal with these issues, I'd go with that solution because, as ic-racer said, there are heads available at pretty reasonable prices now-a-days. You WILL need the longer lift rods if you do.
I was mostly satisfied with the MEL head as it solved both of those problems for me with a 'bolt-on' solution. I'm a decent housekeeper so dust was not an insurmountable isssue. However, as I stated in my original post, I wanted to start using Ross masking method which requires a diffusion head. That's what took me down this build path.
Best, Jim
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Re: LED Diffusion Lighthead for Omega D5
The thread indicates "D5" and I read it a number of times without seeing; the pictures are so small I did not notice you using this on a D5500 chassis. I use those with the D5500 color head. I have 3 heads and 3 controllers and enough spares to make one more head. This is one of those threads I'll save as a reference. If I made a LED head like that I think I could fit it in one of my spare D5500 head shells.
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Re: LED Diffusion Lighthead for Omega D5
Quote:
Originally Posted by
ic-racer
The thread indicates "D5" and I read it a number of times without seeing; the pictures are so small I did not notice you using this on a D5500 chassis. I use those with the D5500 color head. I have 3 heads and 3 controllers and enough spares to make one more head. This is one of those threads I'll save as a reference. If I made a LED head like that I think I could fit it in one of my spare D5500 head shells.
Hi ic-racer,
Actually, I'm not sure that I stated this but my enlarger is officially an Omega ProLab II. After the failure of Omega to capture a significant market with the automated D5500, they introduced the ProLab II enlarger which was essentially a D5 lamp housing and negative stage mated to a D5500 column. See KEH's description here.
I typically call it a D5 because that's the compatibility model most folks know. I felt that the fact that it was a ProLab II not relevant to the project. Sorry for the confusion.
Best, Jim
Re: LED Diffusion Lighthead for Omega D5
No confusion, just a belated "congratulations for having what I think is the best 4x5 enlarger Omega made." It was a great system, allowing both the lift or cassette style negative holders and automated or manual heads.
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Re: LED Diffusion Lighthead for Omega D5
Just so others that are not familiar with these enlargers know, a LED head like you constructed can sit right on the cassette negative holder and be bolted to the cassis. In that case the lift mechanism is not needed.
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